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Lessons Learned:Gravity Probe B Data Analysis

October 15, 2005

Sasha Buchman

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The Relativity Mission ConceptThe Relativity Mission Concept

ee R

R

R

Rc

GIR

Rc

GM 232

132

3

241

2

1v

Launched April 20, 2004Start Science August 27, 2004Liquid He exhausted September 29, 2005

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UNDERSTAND THE INSTRUMENT

“New Instrument” In Space• Noise• Sensitivities

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The Instruments: GPB and LISA

13 mHz 0.1 mHz-1 Hz

• 4 Gyroscopes • 6 GRS

• 1 Telescope • 6 Telescopes

• 1 Spacecraft • 3 Spacecraft

• Thermally Controlled • Thermally Controlled

• 4 SQUIDs

• 3 Interferometers

• 9 DOF Control • 57 DOF Control

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The Data: GPB and LISA

13 mHz 0.1 mHz-1 Hz

• 2 kbytes/sec TDRSS @ 2-12 hours/day DSN

• 32 kbytes/sec direct ground @ 4/day

• ~ 700 sensors

• ~ 10,000 monitors

• Regular data: 0.1-1 Hz

• Snapshots: 220-2200 Hz

• >100,000 commands

• ~ 1 Terabytes/year recorded

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Recommendations

• Extensive ground simulator with hardware in the loop

• Full instrumentation of all systems

• Comprehensive periodical instrument calibrations

• Maximum instrumentation data to ground

• Fast data snapshots to ground

• Critical data processing on the ground

• Maximum ‘instrument time’ allocation in Data Analysis